Method and apparatus for molding an insulator device

ABSTRACT

A molding tool for insert-molding an insulator having a terminal section and an insulating section, the terminal section having a base portion and an upright portion projecting upward from the base portion, the molding tool having a fixed portion contacting against the base portion of the terminal section for support during molding, and a movable portion having a tip holding section for contacting against a tip of the upright portion of the terminal section and a side supporting projection section for contacting against a portion of a side of the upright portion of the terminal section for support during molding, wherein the movable portion is positioned during molding above the fixed portion to form a molding space therebetween along the base portion and extending upwardly toward the tip of the upright portion of the terminal section, but excluding the tip and the portion of the side of the upright portion that contacts against the movable portion, such that when insulation is injected into the molding space during molding to form an insulation section, the side supporting projection section of the movable portion prevents the upright portion of the terminal section from deforming.

TECHNICAL FIELD

The present invention relates to a device for molding a terminalcomposed of a base end and a resin section molded in an area extendingfrom the base end to the halfway to a tip end.

BACKGROUND ART

For example, an insulator used in a switching device has such astructure as shown in FIGS. 6 and 7. The insulator 1 includes a terminal2 bent at a substantially right angle at a bending section 2a at a baseend. A resin section 3 having an electric insulating property isprovided at the base end and an area of the halfway to a tip end 2bstanding from the base end of the terminal 2.

The insulator 1 having such a structure has been conventionallyinsert-molded by a molding tool 4 as shown in FIGS. 8 and 9.Specifically, the molding tool 4 is composed of a fixed part 5 and amovable part 6. With the tip end 2b of the terminal 2 inserted in aholding section 6a of the movable part 6, molding resin 8 is poured intoa molding space 7 formed in the molding tool 4 and solidified.Thereafter, the molding resin 8 is taken out from the molding tool 4 tomold the insulator 1.

However, in the above structure, the terminal is apt to become deformed,as indicated by a two-dot chain line in FIG. 8, owing to the pressure ofthe resin 8 flowing through the molding space in molding the resinsection 3 (the direction of flow of the resin 8 is indicated by arrowA). In order to prevent such deformation, the thickness, width, heightor strength of material of the terminal 2 is limited and hence thefreedom of design is greatly restricted.

Therefore, an object of the present invention is to provide a device formolding a resin section of a terminal without causing the deformation ofa terminal, which can widen the degrees of freedom in the strength anddesign of the terminal.

DISCLOSURE OF THE INVENTION

In order to attain the above object, the present invention, in a devicefor molding a terminal device in which in a state where the tip end of aterminal bent at a base end is held in a molding tool, resin havingelectrically insulating property is poured into a molding space of themolding tool to mold a resin section at the base end of the terminal andan area from the base end to the halfway to the tip end of the terminal,is characterized in that a supporting projecting section is provided inthe movable part of the molding tool and, at the time of molding theresin section, the face of the terminal on the opposite side of the facewhich is apt to receive the pressure of a resin flowing in-a moldingspace is brought into contact with the supporting projecting section.

In accordance with the means described above, at the time of molding theresin section of the terminal device, even if the face which is apt toreceive the pressure of the resin flowing in the molding space of theterminal receives the pressure of the resin, in the terminal, the faceof the terminal on the opposite opposite side of the face which is aptto receive the pressure of the resin is supported by the supportingprojecting section. Therefore, the deformation of the terminal by thepressure of the resin can be prevented surely.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal sectional view showing one embodiment of thepresent invention;

FIG. 2 is a sectional view taken in line a--a in FIG. 2;

FIG. 3 is a broken perspective view of the insulator;

FIG. 4 is a plan view of a terminal portion;

FIG. 5 is a left side view of the terminal portion partially broken;

FIG. 6 is a view corresponding to FIG. 3 showing a prior art;

FIG. 7 is a view corresponding to FIG. 4;

FIG. 8 is a view corresponding to FIG. 1; and

FIG. 9 is a sectional view taken in line b--b in FIG. 8.

EMBODIMENTS

Now referring to FIGS. 1-5, an explanation will be given of anembodiment of the present invention.

FIGS. 3-5 show the state of an insulator 11 serving as a terminal deviceafter it has been molded. The insulator 11 includes a terminal 12 bentat a substantially right angle at a bending section 12a at a base end. Aresin section 13 having an electric insulating property is provided atthe base end and an area of the halfway to an tip end 12b standing fromthe base end of the terminal 12. In this case, in the resin section 13,on the one side of an upright section 13a along the terminal 12, agroove section 14 is formed along the terminal 12.

The insulator 11 having such a structure is insert-molded by a moldingtool 15 as shown in FIGS. 1 and 2. Specifically, the molding tool 15 iscomposed of a fixed part 16 and a movable part 17. A molding space 18 isformed between the fixed part 16 and the movable part 17.

The movable part 17 includes a holding section 19 for supporting a tipend 12b of the terminal 12 and a supporting projection section 20 incontact with the left side of the terminal 12 which are formedintegrally. The supporting projecting section 20 extends from theholding section 19 to the halfway of the base end of the terminal 12.

Thus, where the resin section 13 of the insulator 11 is molded, first,with the terminal 12 set in the molding tool 15, the movable part 17 isclamped to the fixed part 16. In this case, with the tip end 12b of theterminal 12 inserted and held in the holding section 19 of the movablepart 17, the left side 12c of the terminal 12 is brought into contactwith the supporting projecting section 20. In this state, molding resin21 is poured into the molding space 18 of the molding tool 15 (thedirection of flow of the resin 21 is indicated by arrow A in FIG. 1) andsolidified.

At this time, even if the right side 12d, which is apt to receive thepressure of the resin 21 flowing through the molding space, receives thepressure of the resin 21, the left face 12c of the terminal 12, which ison the opposite side of the face which is apt to receive to the pressureof the resin 21, is supported by the supporting projecting section 20 sothat the deformation of the terminal 12 due to the pressure of the resin2 can be surely prevented.

The resin 21 is solidified and thereafter taken out from the moldingtool 15. Thus, the insulator 11 (FIGS. 3-5) is fabricated. In this case,in the terminal 12, the tip end 12b held in the holding section 19 isexposed from the resin section 13. Further, in the resin section 13, agroove 14 is formed at the area where the supporting projecting section20 is located.

In accordance with this embodiment, the supporting projecting section 20is provided in the movable part 17 of the molding tool 15 and, at thetime of molding the resin section 13, the left face 12c of the terminal12 on the opposite side of the right face 12d which is apt to receivethe pressure of the resin 21 flowing in the molding space 18 is broughtinto contact with the supporting projecting section 20. Therefore, thedeformation of the terminal 12 by the pressure of the resin 21 can beprevented surely. Thus, the degrees of freedom in the strength(thickness, width or height of the terminal 12 or hardness of thematerial) and hence design of the terminal can widened.

In the above embodiment, the insulator 11 has been molded as theterminal device. However, the present invention can be applied to thedevice for molding a connector in which a case section of resin isprovided in a terminal by molding.

As apparent from the explanation hitherto made, in accordance with thepresent invention, at the time of molding the resin section of theterminal device, even if the face which is apt to receive the pressureof the resin flowing in the molding space of the terminal receives thepressure of the resin, the face of the terminal on the opposite side ofthe face which is apt to receive the pressure of the resin is supportedby the supporting projecting section. Therefore, the deformation of theterminal by the pressure of the resin can be prevented surely. Thus, thedegrees of freedom in the strength (thickness, width or height of theterminal 12 or hardness of the material) and hence design of theterminal can widened. Thus, the degrees of freedom in the strength andhence design of the terminal can be widened.

What is claimed is:
 1. A molding tool for insert-molding an insulatormaterial around portions of a terminal, comprising:a fixed portion forsupporting the terminal; and a movable portion having a supportingprojecting section for contacting a portion of the terminal duringmolding, and having a molding space formed about remaining portions ofthe terminal, such that the supporting projection section prevents theterminal from deforming when the molding space is injected with theinsulator material around portions of the terminal wherein the terminalhas a base portion and an upright portion projecting upward from thebase portion.
 2. The molding tool according to claim 1, wherein thefixed portion contacts the base portion of the terminal for supportduring molding, and the movable portion has a tip holding section forcontacting a tip of the upright portion of the terminal during molding.3. The molding tool according to claim 1, wherein the supportingprojection section contacts a side of the upright portion of theterminal.
 4. A molding tool for insert-molding an insulator having aterminal section and an insulating section, the terminal section havinga base portion and an upright portion projecting upward from the baseportion, the molding tool comprising:a fixed portion contacting the baseportion of the terminal section for support during molding; and amovable portion having a tip holding section for contacting a tip of theupright portion of the terminal section and a side supporting projectionsection for contacting a portion of a side of the upright portion of theterminal section for support during molding, whereinduring molding themovable portion is positioned above the fixed portion to form a moldingspace therebetween along the base portion and extending upwardly towardthe tip of the upright portion of the terminal section, such that wheninsulation is injected into the molding space during molding to form aninsulation section, the side supporting projection section of themovable portion prevents the upright portion of the terminal sectionfrom deforming.
 5. The molding tool according to claim 4, wherein theside supporting projection section of the movable portion contacts onlya portion of the side of the upright portion of the terminal section. 6.A method for insert-molding an insulator having a terminal section andan insulating section, the terminal section having a base portion and anupright portion projecting upward from the base portion, comprising thesteps of:supporting the base portion of the terminal section against afixed surface; placing a mold upon the terminal section to contactagainst a tip and only a portion of a side of the upright portion of theterminal section, thereby forming a molding space along the base portionand extending upwardly toward the tip of the upright portion of theterminal, but excluding the tip and the portion of the side of theupright portion that contacts against the movable portion; and injectinginsulation into the molding space to form an insulation section,whereinthe side of the upright portion of the terminal section contactsagainst the mold to prevent the upright portion from deforming as theinsulation is pressed against the upright portion of the terminalsection during molding.
 7. A molding tool for insert-molding aninsulator having a terminal section and an insulating section, theterminal section having a base portion and an upright portion projectingupward from the base portion, the molding tool comprising:a fixedportion contacting the base portion of the terminal section for supportduring molding; and a movable portion having a tip holding section forcontacting a tip of the upright portion of the terminal section and aside supporting projection section for contacting a portion of a side ofthe upright portion of the terminal section when positioned above thefixed portion during molding, such that a molding space is formed alongthe base portion and extending upwardly toward the tip of the uprightportion of the terminal section, and the side supporting projectionsection of the movable portion prevents the upright portion of theterminal section from deforming when insulation is injected into themolding space during molding to form the insulation section of theinsulator.
 8. The molding tool according to claim 7, wherein the sidesupporting projection section of the movable portion contacts only aportion of the side of the upright portion of the terminal section.